1. Field of the Invention
The present invention relates to an antenna apparatus used in a relay unit.
2. Description of the Related Art
As an antenna for relay which re-transmits ground wave for a mobile phone, television broadcast, or the like to a blind zone such as an underground mall, a small-sized and weight-reduced antenna is demanded in view of a problem about an installation place, aesthetic purposes or the like. As an antenna for relay, vertical polarized and horizontal-plane nondirectional antenna is frequently used.
As a known technique relating to the present invention, a bidirectional polarized antenna apparatus which is provided with a bidirectional antenna for horizontal polarization having a plurality of linear radiating element portions configured to excite a linear or planar impedance matching element portion according to one-point power feeding from a back thereof and provided perpendicularly to the matching element portion, a plurality of distal ends of the linear radiating element portions being grounded, and a grounding plater where the bidirectional antenna for horizontal polarization is disposed on the grounding plate is known (see, Jpn. Pat. Appln. KOKAI Publication No. 11-205036).